Negative climate feedback: more ships in the Arctic mean more cooling

This article claim ships will “be able to sail right over the North Pole” by 2050 due to warming, but at the same time say ship tracks will make more clouds and cool the Arctic. Of course, anything is possible with the help of climate models.

More ships and more clouds mean cooling in the Arctic

With sea ice in the Arctic melting at an alarming rate, opportunities for trans-Arctic shipping are opening up, and by mid-century ships will be able to sail right over the North Pole – something not previously possible for humankind.

UConn geographer Scott Stephenson and colleagues say the growth of trans-Arctic shipping and the increase in emissions that will accompany it may offset some of the overall warming trend in the Arctic by the end of the century. Their study was published Sept. 12 in Geophysical Research Letters.

At the same time, they caution that this effect is relatively minor in the context of overall global warming, and that more ships in the Arctic would heighten the risk of environmental disasters.

By modeling changes in climate trends associated with increases in shipping traffic and subsequent increases in emissions, the researchers found that trans-Arctic shipping offsets some of the overall warming trend in the Arctic by the end of the century.

“The results surprised us,” says Stephenson, an assistant professor of geography in the College of Liberal Arts and Sciences. “We didn’t know if we would see a clear signal of warming or cooling, and the fact that we saw a clear cooling trend was unexpected.”

Scientists have been aware for some time that shipping routes may affect climate in two competing ways, Stephenson says. With an increase in emissions, there is an increase in black carbon released. This sooty black carbon settles on highly reflective surfaces such as snow and ice, reducing the reflection of solar radiation, meaning the surfaces hold the radiation as heat.

The other way shipping emissions affect climate is through the sulfur dioxide released as another bi-product of fuel combustion. Rather than warming, however, Stephenson says the sulfur emissions play a role in cooling by encouraging the formation of cloud droplets and by scattering incoming sunlight.

Ship tracks form when very small, airborne particles emitted in the exhaust of large ships (and airplanes) attract water molecules, acting as ‘seeds’ (or ‘cloud condensation nuclei’) for clouds. Continued accumulation of droplets on the cloud condensation nuclei forms the thin, streaky clouds. “This is why you often see a trailing track of clouds following ships,” he says. “They call those ship tracks.”

Ship tracks form when very small, airborne particles emitted in the exhaust of large ships (and airplanes) attract water molecules, acting as ‘seeds’ (or ‘cloud condensation nuclei’) for clouds. Continued accumulation of droplets on the cloud condensation nuclei forms the thin, streaky clouds pictured in this image. “This is why you often see a trailing track of clouds following ships,” he says. “They call those ship tracks.” Image: NASA

Although the impacts of emissions have been investigated in the past, Stephenson says this study presents a more realistic and robust scenario, as it builds on the earlier studies and uses a fully coupled Earth system model, including projected emissions for future trans-Arctic shipping from 2006 to 2099, making it more dynamic.

The team also took into account the changing nature of sea ice through the seasons and how that would impact shipping routes. With shifts in shipping routes come shifts in where emissions would be deposited.

“Previous studies have more or less treated Arctic shipping routes as static, meaning the routes do not vary with the season and with the growth and shrinking of the ice,” Stephenson says. “We believe this is an important piece of the puzzle – to better model where ships might be able to go over the course of the 21st century.”

Shipping trends were estimated by taking into account the necessary transport of goods for each Europe to Asia port per month. Fuel needs were calculated and emission totals were determined.

The researchers also factored in global anthropogenic (human-caused) greenhouse gas concentration trajectories, adopted by the International Panel on Climate Change (IPCC), at a level closely aligning with today’s trends, along with global economic output that will drive the transport of goods.

“We attempted to fully integrate the interactions between the various components of the climate system in ways that have not been done before,” Stephenson says.

The main result was that the cooling effect won out over the warming effect in the simulations, to the tune of about one degree Celsius.

Yet Stephenson cautions that, although it’s a clear cooling result, it’s relatively minor in the grand scheme of global warming projected in the Arctic: “We’re talking about a slowing of the warming, but not a halting of the warming.”

The Arctic continues to warm at twice the global average, and though increased shipping will likely have a cooling impact on the region, the researchers stress that these results should not be interpreted as an endorsement for Arctic shipping, especially as a potential solution to climate change.

Stephenson notes that while trans-Arctic shipping routes would cut travel time by as much as 40 percent, growth in shipping traffic would mean heightened risk of oil spills and clearer access to extractable resources such as oil, gas, and minerals in the region – all scenarios that come with potentially dire environmental consequences should an accident occur. With fewer amenities within reach to respond to a potential disaster, responders would be faced with huge logistical challenges to deal with those scenarios.

“There are clear economic benefits to shipping in the Arctic, with shorter routes and less fuel being burned,” he says, “but there are also enormous potential risks.”

Additionally, the cooling could be offset by international regulation and trade agreements, for instance if planned global limits on sulfur emissions from fuel used by the ships go into effect. Without the sulfur-induced cloud formation, the cloud-driven cooling effect will not happen.

Stephenson concludes, “The mild cooling shown by these results is, we think, a significant piece in the puzzle of understanding the complexities of the interactions between humans and the climate system. It’s important to take account of this.”

43 thoughts on “Negative climate feedback: more ships in the Arctic mean more cooling”

With sea ice in the Arctic melting at an alarming rate, opportunities for trans-Arctic shipping are opening up, and by mid-century ships will be able to sail right over the North Pole – something not previously possible for humankind.

I for one would like to know where the source of their data came from which determines that “Sailing across the North Pole” is something that was “Not previously possible for humankind”? How have they determined that 1000 or 2000 or more years ago, there wasn’t Ice Free conditions at the pole.
Sounds like Modeled Assumptions to me

The Northwest Passage was almost certainly open and navigable 1000 years ago.
There is no indication the Vikings ever gave it a try. They either could not see a reason to try, or saw thay it was a really dumb thing to do. I cannot think of anybody else even remotely connected to Western civilization in the area at the time.

Most likely they began to run into the Inuit and other native tribes, met a less than warm reception, and turned back. If the MWP had lasted a half-century longer, Greenland might have provided the Vikings a base from which to make forays into North America.

“Condensation nuclei detectors” are hardly new; the US Navy’s old P2V and P3A ASW aircraft had a “condensation nuclei detector” called “Sniffer” that sampled the air and could lead the aircraft to a ship or snorkeling submarine, back in the 1950’s. It was phased out once nuclear submarines became more common in the Soviet fleet.

I think we are going to see more LNG powered ships over time eliminating the particulates and aerosols. Certainly going to take a long time for this to become the common method as existing ships won’t be retrofitted.

I think the reference is to the use of ship’s diesel generators in port. Most passenger ships carry both heavy oil and light oil. Heavy oil (cheap) for use at sea, and light oil (expensive) for use in port.

the excuses ahead of the down turn in the amo coming in early i see. that must have been a very, very still period above the arctic to get all those neat lines from ships travelling at a few knots in straight lines with no turns if that is a genuine image.

Oh, it is genuine alright and you are right the air is very still. These ‘ship tracks’ form when a high pressure (with a nice warm inversion) sits over cold water. High pressure=little wind. These ship tracks are quite common over the waters off southern California when the southeastern quadrant of the subtropical high (which has a very strong inversion) sits over the cold waters of the California Current.

“The researchers also factored in global anthropogenic (human-caused) greenhouse gas concentration trajectories, adopted by the International Panel on Climate Change (IPCC), at a level closely aligning with today’s trends, along with global economic output that will drive the transport of goods.”

They used RCP 8.5 – (as you would expect)

And of course “With sea ice in the Arctic melting at an alarming rate…..” as already noted by other commenters.

There’s a definite lack of correlation between the world these people live in and what the rest of us call the real world.

And then these gonzos add that they could always regulate the sulphur out of fuels so they could … wait for it… prevent the cooling!! Do they understand how idiotic they sound to anyone with an IQ over 80.

The ships will be nuke fueled without a shadow of a doubt, probably purchased from Russia which is very advanced with a fleet of new nuke icebreakers which are the world’s largest. Do the CO2 addled brains of Europe and possibly America, certainly Canada, not stop to wonder why Russia built these ships? By the time we decide to get into rhe fray, the Arctic oil gas and minerals will be under Roosky production.

What they claim are “ship tracks”, sure look like airplane contrails
Isn’t it amazing how they get ship exhaust so high up in altitude?

“The results surprised us,” says Stephenson, an assistant professor of geography in the College of Liberal Arts and Sciences. “We didn’t know if we would see a clear signal of warming or cooling, and the fact that we saw a clear cooling trend was unexpected.”

With sea ice in the Arctic melting at an alarming rate, opportunities for trans-Arctic shipping are opening up, and by mid-century ships will be able to sail right over the North Pole – something not previously possible for humankind.
————————————
That should be enough to tell you not to bother reading any farther.

For permission, contact us. See the About>Contact menu under the header.

All rights reserved worldwide.

Some material from contributors may contain additional copyrights of their respective company or organization.

We use cookies to ensure that we give you the best experience on WUWT. If you continue to use this site we will assume that you are happy with it. This notice is required by recently enacted EU GDPR rules, and since WUWT is a globally read website, we need to keep the bureaucrats off our case!
Cookie Policy